Coextruded multilayer plastic container utilizing post consumer plastic

Abstract

A coextruded multilayer plastic container utilizing post consumer plastic resin comprising an appearance enhancing thin outer layer of ethylene polymers, which enhances the appearance of the container, an intermediate layer comprising a fusion blend of post consumer resin with or without colorant and a third layer comprising a fusion blend of post consumer resin which may have mixed colors. In a modified and preferred form, a fourth inner layer of virgin ethylene polymer is provided.

We claim: 
     
       1. A multilayer coextruded and blow molded hollow plastic container which has a side wall consisting essentially of a thin outer plastic layer comprising a fusion blend of virgin plastic resin and an appearance enhancing additive,   said appearance enhancing additive being selected from the group consisting of pigments providing bright attractive colors, flakes for providing pearlescent effects, fluorescent dyes of pigments which absorb light of one wave length and polymers of selected molecular weights which provide a high gloss appearance, or mixtures thereof,   a thin intermediate opaque plastic layer comprising a fusion blend of post consumer resin with colorants heat bonded to the outer layer during coextrusion without adhesives,   a relatively thick inner plastic layer having a thickness greater than the thickness of the outer plastic layer and the intermediate opaque plastic layer comprising post consumer resin heat bonded to the intermediate layer during coextrusion without adhesives,   said post consumer resin comprising the major portion by weight of the container, and   said thin intermediate plastic layer masking the post consumer resin in said relatively thick inner plastic layer.   
     
     
       2. The plastic container set forth in claim 1 wherein said thin outer plastic layer comprises ethylene polymers selected from the group consisting of linear low density polyethylene, low density polyethylene, high density polyethylene, or mixtures thereof. 
     
     
       3. The plastic container set forth in claim 2 whereto said thin intermediate plastic layer comprises a fusion blend of post consumer resin primarily the plastic from high density polyethylene homopolymer containers used for packaging milk and colorant. 
     
     
       4. The plastic container set forth in claim 3 wherein said thick inner plastic layer comprises a fusion blend of post consumer resin including post consumer resin from colored plastic containers and regrind. 
     
     
       5. The plastic container set forth in claim 1 wherein said thin intermediate plastic layer comprises a fusion blend of post consumer resin primarily the plastic from high density polyethylene homopolymer containers used for packaging milk and colorant. 
     
     
       6. The plastic container set forth in claim 5 wherein said thick inner plastic layer comprises said post consumer resin including post consumer resin from colored plastic containers and regrind. 
     
     
       7. The plastic container set forth in any one of claims 2, 3-6 including a coextruded thin layer of plastic resin overlying said inner layer. 
     
     
       8. The plastic container set forth in claim 7 wherein said coextruded thin layer overlying said inner layer comprises virgin high density copolymer resin overlying the inner layer and heat bonded to the inner layer during coextrusion without adhesives. 
     
     
       9. The container set forth in claim 7 wherein said coextruded thin inner layer overlying said inner layer comprises solvent resistant plastic resin overlying the inner layer and bonded thereto by a coextruded layer. 
     
     
       10. The container set forth in claim 9 wherein said solvent resistant plastic resin comprises nylon including a coextruded adhesive layer between the intermediate opaque layer and the inner layer of post consumer resin and a coextruded adhesive layer between the inner layer of post consumer resin and said further inner layer of solvent resistant plastic, each said adhesive layer comprising a nylon/polyethylene adhesive. 
     
     
       11. The plastic container set forth in claim 7 wherein said thin layer overlying said thin layer comprises virgin high density polyethylene. 
     
     
       12. The container set forth in claim 1 wherein said plastic layers have thicknesses ranging as follows:   ______________________________________                                    
thin outer layer    2-20      mils                                        
thin intermediate layer                                                   
                    2-10      mils                                        
thick layer         5-30      mils.                                       
______________________________________                                    
     
     
     
       13. The container set forth in claim 7 wherein said layers have thicknesses ranging as follows:   ______________________________________                                    
thin outer layer       2-20 mils                                          
thin intermediate layer                                                   
                       2-10 mils                                          
thick layer            5-30 mils                                          
thin inner layer       1-10 mils.                                         
______________________________________                                    
     
     
     
       14. A method of forming a multilayer coextruded plastic container comprising coextruding a multilayer parison consisting essentially a thin outer plastic layer comprising a fusion blend of virgin plastic resin and an appearance enhancing additive, a thin intermediate opaque plastic layer comprising a fusion blend of a post consumer resin with colorants heat bonded to the outer layer during coextrusion without adhesives, and a relatively thick inner layer having a thickness greater than the thickness of the outer plastic layer and the intermediate opaque plastic layer comprising post consumer resin heat bonded to the intermediate layer during coextrusion without adhesives, said intermediate layer masking the post consumer resin,   said appearance enhancing additive being selected from the group consisting of pigments providing bright attractive colors, flakes for providing pearlescent effects, fluorescent dyes of pigments which absorb light of one wave length and polymers of selected molecular weights which provide a high gloss appearance, or mixtures thereof,   said post consumer resin comprising the major portion by weight of the container, and   blow molding the multilayer parison to form a multilayer container wherein the thin intermediate plastic layer masks the post consumer resin in said relatively thick inner plastic layer.   
     
     
       15. The method set forth in claim 14 wherein said thin outer plastic layer comprises ethylene polymers selected from the group consisting of linear low density polyethylene, low density polyethylene, high density polyethylene, or mixtures thereof. 
     
     
       16. The method set forth in claim 15 wherein said intermediate plastic layer comprises a fusion blend of post consumer resin primarily from high density polyethylene homopolymer containers used for packaging milk and colorant. 
     
     
       17. The method set forth in claim 16 wherein said thick inner plastic layer comprises said post consumer resin including post consumer resin from colored plastic containers and regrind. 
     
     
       18. The method set forth in claim 15 wherein said intermediate plastic layer comprises a fusion blend of post consumer resin primarily from high density polyethylene homopolymer containers used for packaging milk and colorant. 
     
     
       19. The method set forth in claim 18 wherein said thick inner plastic layer comprises consumer resin including post consumer resin from colored plastic containers and regrind. 
     
     
       20. The method set forth in any one of claim 16, 16-19 including coextruding a thin layer of plastic resin overlying said inner layer. 
     
     
       21. The method set forth in claim 20 wherein said coextruded thin layer overlying said inner layer comprises virgin high density copolymer resin overlying the inner layer and heat bonded to the inner layer during coextrusion without adhesives. 
     
     
       22. The method set forth in claim 20 wherein said coextruded thin inner layer comprises solvent resistant plastic resin overlying the inner layer and bonded thereto by a coextruded layer. 
     
     
       23. The method set forth in claim 22 wherein said solvent resistant plastic resin comprises nylon including coextruding an adhesive layer between the intermediate opaque layer and the inner layer of post consumer resin and coextruding an adhesive layer between the inner layer of post consumer resin and said further inner layer of solvent resistant plastic, each said adhesive layer comprising a nylon/polyethylene adhesive. 
     
     
       24. The method set forth in claim 20 wherein said thin layer comprises virgin high density polyethylene. 
     
     
       25. The method set forth in claim 14 wherein said layers have thicknesses ranging as follows:   ______________________________________                                    
thin outer layer    2-20      mils                                        
thin intermediate layer                                                   
                    2-10      mils                                        
thick layer         5-30      mils.                                       
______________________________________                                    
     
     
     
       26. The method set forth in claim 20 wherein said layers have thicknesses ranging as follows:   ______________________________________                                    
thin outer layer       2-20 mils                                          
thin intermediate layer                                                   
                       2-10 mils                                          
thick layer            5-30 mils                                          
thin inner layer       1-10 mils.                                         
______________________________________